Final push for Pluto's postage stamp

More than 11,000 people have signed an online petition to honor NASA's mission to Pluto and other denizens of the solar system's icy rim with a commemorative U.S. postage stamp — which is a fine way to celebrate the 82nd anniversary of Pluto's planetary coming-out party.

"I'm pretty happy," said Alan Stern, a planetary scientist at the Southwest Research Institute who is the principal investigator for NASA's New Horizons mission. New Horizons is due to fly by the dwarf planet in 2015, and Stern is among the leading supporters of the stamp campaign.

"A lot of stamps get 1,000 petition names, and they're very happy with that," Stern told me. "Still, I'd rather have 12,000 than 11,000."

Tuesday marks the 82nd anniversary of the announcement of Pluto's discovery by Clyde Tombaugh at the Lowell Observatory in Arizona, and it also marks a turning point for the petition drive. Stern said he and his colleagues are now turning their attention to the preparation of a formal proposal that will be submitted to the Citizen Stamp Advisory Committee next month.

Years-long processBack in 1991, the U.S. Postal Service issued a set of stamps honoring NASA's interplanetary missions — but the set included a stamp picturing Pluto, with the legend "Not Yet Explored." The $700 million New Horizons mission aims to cancel that earlier stamp's sentiment, and Stern is hoping that a brand-new New Horizons stamp will provide a stickable way to set the record straight.

The half-ton, piano-sized New Horizons probe was launched in 2006 and has made its way well beyond the orbit of Uranus, but it'll probably be another three years before most people sit up and truly take notice of the mission, Stern said. New Horizons' view of Pluto's surface features should match the resolution of the Hubble Space Telescope around April 2015.

Why start so early on the stamp? That's just the way things are done: Proposals for commemorative stamps are considered by the advisory panel, and recommendations are then forwarded to the postmaster general for a final decision. "I don't think we're going to hear anything for two to three years," Stern said.

That time frame sounds about right to Robert Z. Pearlman, editor of the CollectSpace online publication and an expert on space history and memorabilia. "We'll probably know if it's a success in mid-2014," he said. Pearlman based that estimate on the circumstances surrounding the stamp that commemorated NASA's Messenger mission to Mercury. In Messenger's case, postal officials announced in August 2010 that the stamp would be part of its lineup. That was followed by its issuance in May 2011.

Spacecraft in semi-slumberThe New Horizons spacecraft has been rousing itself from hibernation every week to transmit status signals confirming that it's still on course and healthy (the so-called "green beacon"). Stern said the spacecraft is due to wake up fully on April 30 for "a very intensive couple of months of activities," aimed at rehearsing the procedures that will be used for the flyby of Pluto and its largest moon, Charon, in July 2015.

Pluto has been the subject of a lot of discussion since New Horizons was launched: In August 2006, the International Astronomical Union voted to classify the icy world as a "dwarf planet" rather than a major planet — a move that was widely seen as a demotion. March 13, the date on which Pluto's discovery was announced in 1930, has become known in some circles as "Pluto Day." It's a day to draw attention to the little guys of the solar system, and as the author of "The Case for Pluto," I can't help but keep it on my holiday calendar.

Glenn Fleishman via Twitpic

Tim Lloyd hoists a protest sign during a Pluto Day rally in Seattle on Saturday.

Over the weekend, I was among about 30 grown-ups and kids who attended an early Pluto Day rally at the Greenwood Space Travel Supply Co. in Seattle. At the appointed time, we raised our protest signs, marched down the sidewalk and shouted good-natured chants ("Can't stop the power, the power of the Pluto, 'cause the power of the Pluto don't stop") as well as edgier ones ("Hey, hey, ho, ho, the IAU has got to go"). My favorite placard read, "Keep your laws off my icy body."

At the end of the block-long march (on both sides of the street), we gathered at a local coffee shop for a teach-in about dwarf planets. The climax was a rock-paper-scissors contest to decide whether or not Pluto was an honest-to-goodness planet. I'm happy to report that I triumphed in a two-out-of-three match against University of Washington astronomer Toby Smith.